The present invention relates to a connector for use in connecting a small-sized thin-profile card, such as an IC card.
Recently, an IC card is remarkably wide spread. Even a small-sized apparatus, such as a mobile telephone, which can always be carried by a user is provided with a connector for connecting the IC card. The connector of the type is required to have a thin profile and to have a function of protecting the IC card.
In order to meet the above-mentioned requirement, proposal is made of a connector comprising a housing fixedly holding a contact, and an openable/closable cover for pressing a mating object to be connected against the contact to establish electrical connection. In the above-mentioned connector, the IC card is inserted and removed while the cover is opened. After completion of insertion or removal of the IC card, the cover is closed and a part of the cover is engaged with the housing to be locked.
As the connector of the type, there is known a connector which essentially requires the cover to be moved, sliding along the housing in order to unlock the cover (see Japanese Unexamined Patent Publications Nos. H10-106674, H11-167968, and 2000-260537). In the connector of this type, the cover is not unlocked unless the cover is slid along the housing. Therefore, during normal use, it is unlikely that the cover is unintentionally and erroneously opened.
In particular, the connector disclosed in Japanese Unexamined Patent Publication No. H10-106674 has a metallic cover in order to achieve a thin profile. In order to hold the cover to be rotatable and slidable with respect to the housing, a long slot formed in the cover is engaged with a shaft portion formed on the housing.
The connector disclosed in Japanese Unexamined Patent Publication No. 2000-260537 also has a metallic cover in order to achieve a thin profile, like the connector disclosed in Japanese Unexamined Patent Publication No. H10-106674.
However, in each of the connectors disclosed in Japanese Unexamined Patent Publications Nos. H10-106674, H11-167968, and 2000-260537, the cover may slide along the housing to be unlocked and opened if the connector is subjected to strong mechanical shock, for example, when an apparatus equipped with the connector is dropped. In case where the cover is unintentionally and undesiredly opened, it is highly possible to cause instantaneous interruption or permanent interruption of a signal. The above-mentioned problem is difficult to solve merely by weak frictional engagement between the cover and the housing. On the contrary, if the frictional engagement is strong, it is difficult to perform an operation of opening the cover.
If the cover is provided with the long slot, the cover may be displaced from a proper position during rotation. In this event, one end of the cover may be butted against a substrate with the connector mounted thereto, thereby preventing smooth rotation of the cover. In order to avoid the above-mentioned problem, Japanese Unexamined Patent Publication No. H10-106674 adopts a structure in which the cover is allowed to rotate after an axis moves from its initial position to a rotatable position. In this structure, however, a thin profile can not be achieved because of protrusion of one end of the cover during rotation. In order to prevent the displacement of the axis during rotation, the long slot is divided into a circular part (rotating portion) and a rectangular part (sliding portion) in the above-mentioned publication. However, since the shaft portion is integrally formed with the housing made of resin susceptible to wear, the effect of such a two-part shape does not continue for a long time because of wear of the shaft portion.
According to Japanese Unexamined Patent Publication No. 2000-260537, the above-mentioned disadvantages of Japanese Unexamined Patent Publication No. H10-106674 are removed except the strength of the shaft portion. However, the shaft portion of the metallic cover is formed by an additional or separate piece. This results in an increase in number of parts. Therefore, even if the thin profile can be achieved, the cost will be increased. In case where the shaft made of resin is fixed to the metallic cover, the problem of wear is inevitable. Even if the shaft is configured into a special shape in order to control the operation of the cover, the effect of such a special shape does not continue for a long time, like in Japanese Unexamined Patent Publication No. H10-106674.